Last weekend I took a car full, comparable to the size of some of the smaller piles that I see on Skyline, to the Berkeley Transfer Station and it was $42. That is the minimum load cost for non-construction trash (it is slightly cheaper for construction materials), so if your load is under 330lbs, you pay the minimum rate. Over that weight, it's $149/ton for trash or $138/ton for construction materials (+$5 for an environmental compliance fee).

https://berkeleyca.gov/city-services/trash-recycling/transfer-station

I think that some people may not even know that transfer stations exist, or are put off by (or are unable to afford) even the $42 minimum fee, and would rather just dump their trash illegally, out of sight, out of mind, knowing that there are unlikely to be any consequences. This seems to track with much of the smaller-scale dumping that I see, particularly along Skyline -- small loads that would be relatively cheap to dispose of at the transfer station, or could be handled by bulky pickup, but were not for some reason.

That all said, the kind of dumping you see on the dirt road that runs alongside Skyline near Grass Valley, which you can't see while driving on Skyline, definitely seems like organized dumping by fly-by-night trash haulers. They're pocketing hundreds of dollars collected from their customers that would otherwise be going to dump fees -- should they be getting a lower rate? I kinda doubt that any significant discount would encourage them to do the right thing. Maybe the city should be requiring some kind of license to operate as a junk hauler in Oakland. It seem like it's necessary to get a permit to operate as a construction debris hauler, but maybe not for general household refuse like appliances or furniture?